• 한국수소및신에너지학회논문집
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• 제34권2호
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• pp.149-154
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• 2023

In the Fourth Industrial Revolution, hydrogen energy is in the spotlight. There is a difficulty in commercialization due to the lack of hydrogen infrastructure. Therefore, a lot of hydrogen should be imported and a method using ammonia is the most useful. In this study, using the mixed gas of hydrogen and nitrogen generated when ammonia is decomposed, the hydrogen separation performance is to be tested. Hydrogen was separated using an electrochemical hydrogen compressor based on a fuel cell and the experiment was conducted by changing the ratio of hydrogen and nitrogen. In addition, the performance was also compared by the difference both the pressure and the membrane.

• 한국분말재료학회지
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• 제31권3호
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• pp.220-225
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• 2024

Molten salt reactors represent a promising advancement in nuclear technology due to their potential for enhanced safety, higher efficiency, and reduced nuclear waste. However, the development of structural materials that can survive under severe corrosion environments is crucial. In the present work, pure Ni was deposited on the surface of 316H stainless steel using a directed energy deposition (DED) process. This study aimed to fabricate pure Ni alloy layers on an STS316H alloy substrate. It was observed that low laser power during the deposition of pure Ni on the STS316H substrate could induce stacking defects such as surface irregularities and internal voids, which were confirmed through photographic and SEM analyses. Additionally, the diffusion of Fe and Cr elements from the STS316H substrate into the Ni layers was observed to decrease with increasing Ni deposition height. Analysis of the composition of Cr and Fe components within the Ni deposition structures allows for the prediction of properties such as the corrosion resistance of Ni.

• The Korean Journal of Ceramics
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• 제4권1호
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• pp.47-52
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• 1998

The nonuniformity of energy absorption capability of ZnO varistor is systematically discussed in this paper. The nonuniformity of electrical characteristics and microstructure leads to decrease the energy absorption capability of ZnO varistor. The energy absorption capabilities were measured under different current waves, the experimental results stated that they have highly scattered phenomena. The influences of varistor surface area and nonuniformity of electrical characteristics to the energy absorption capability and the nonuniformity of commercial ZnO varistors were analyzed. There is a high nonuniformity existing in the energy absorption capability of commercial ZnO varistors.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2005년도 제29회 학술발표회 초록집
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• pp.67-67
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• 2005

• Journal of Electrochemical Science and Technology
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• 제15권1호
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• pp.14-31
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• 2024

The text highlights the growing need for eco-friendly energy storage and the potential of metal-organic frameworks (MOFs) to address this demand. Despite their promise, challenges in MOF-based energy storage include stability, reproducible synthesis, cost-effectiveness, and scalability. Recent progress in supercapacitor materials, particularly over the last decade, has aimed to overcome these challenges. The review focuses on the morphological characteristics and synthesis methods of MOFs used in supercapacitors to achieve improved electrochemical performance. Various types of MOFs, including monometallic, binary, and tri-metallic compositions, as well as derivatives like hybrid nanostructures, sulfides, phosphides, and carbon composites, are explored for their energy storage potential. The review emphasizes the quest for superior electrochemical performance and stability with MOF-based materials. By analyzing recent research, the review underscores the potential of MOF-based supercapacitors to meet the increasing demands for high power and energy density solutions in the field of energy storage.

• 한국산업보건학회지
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• 제23권3호
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• pp.205-211
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• 2013

Objectives: 21 sepiolite substances produced in China were investigated for the presence of asbestos in their materials. Materials and methods: In order to identify asbestos in sepiolite substances, test materials were analyzed using a transmission electron microscope equipped with energy dispersive X-ray spectrometer (TEM-EDS) for confirming their shape and components (atomic %). Results: Five of 21 sepiolte substances were asbestos-containing materials. Two chrysotile containing sepiolite proved to be asbestoscontaining materials, as did two chrysotile mixed with tremolite containing sepiolite. 16 sepiolite substances did not contain asbestos materials. Conclusions: When importing sepiolite substances, they must be analyzed to determine if there is asbestos in their materials.

• Carbon letters
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• 제15권1호
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• pp.15-24
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• 2014

As a part of the electromagnetic spectrum, microwaves heat materials fast and efficiently via direct energy transfer, while conventional heating methods rely on conduction and convection. To date, the use of microwave heating in the research of carbon-based materials has been mainly limited to liquid solutions. However, more rapid and efficient heating is possible in electron-rich solid materials, because the target materials absorb the energy of microwaves effectively and exclusively. Carbon-based solid materials are suitable for microwave-heating due to the delocalized pi electrons from sp2-hybridized carbon networks. In this perspective review, research on the microwave heating of carbon-based solid materials is extensively investigated. This review includes basic theories of microwave heating, and applications in carbon nanotubes, graphite and other carbon-based materials. Finally, priority issues are discussed for the advanced use of microwave heating, which have been poorly understood so far: heating mechanism, temperature control, and penetration depth.

• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2018년도 추계학술논문요약집
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• pp.227-228
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• 2018

• Journal of Ceramic Processing Research
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• 제20권1호
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• pp.48-53
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• 2019

Carbon fiber reinforced SiC composites (C/SiC) have high-temperature stability and excellent thermal shock resistance, and are currently being applied in extreme environments, for example, as aerospace propulsion parts or in high-performance brake systems. However, their low thermal conductivity, compared to metallic materials, are an obstacle to energy efficiency improvements via utilization of regenerative cooling systems. In order to solve this problem, the present study investigated the bonding strength between carbon fiber and matrix material within ceramic matrix composite (CMC) materials, demonstrating the relation between the microstructure and bonding, and showing that the mechanical properties and thermal conductivity may be improved by treatment of the carbon fibers. When fiber surface was treated with a nitric acid solution, the observed segment crack areas within the subsequently generated CMC increased from 6 to 10%; moreover, it was possible to enhance the thermal conductivity from 10.5 to 14 W/m·K, via the same approach. However, fiber surface treatment tends to cause mechanical damage of the final composite material by fiber etching.

• Bulletin of the Korean Chemical Society
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• 제33권2호
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• pp.636-640
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• 2012

We modify ZnO nanorods with Zn-porphyrin to obtain the improved characteristics of energy transfer, which is further investigated for the applicability to photovoltaic devices. A nitrogen heterocyclic ligand containing a thiol group is covalently grafted onto the surface of finely structured ZnO nanorods with a length of 50-250 nm and a diameter of 15-20 nm. Zn-porphyrin is then attached to the ligand molecules by the mechanism of metalligand axial coordination. The resulting energy band diagram suggests that the porphyrin-modified ZnO nanorods might provide an efficient pathway for energy transfer upon being applied to photovoltaic devices.